interrogation point vs question mark

interrogation point and question mark both are nouns.

Word	Noun	Adjective	Verb	Adverb
interrogation point	Yes	No	No	No
question mark	Yes	No	No	No

As nouns, interrogation point and question mark are synonyms defined as:

interrogation point and question mark: a punctuation mark (?) placed at the end of a sentence to indicate a question

interrogation point (noun)	question mark (noun)
a punctuation mark (?) placed at the end of a sentence to indicate a question	a punctuation mark (?) placed at the end of a sentence to indicate a question